While these mammals share a name, and the same celebratory day, two-toed and three-toed sloths aren’t closely related and have been separated on the evolutionary tree for millions of years. In both appearance and behavior, they differ in many key ways.
Both animals have three toes on their back feet, but two-toed sloths have, of course, just two toes on their front feet, while three-toed sloths have three toes on their front feet.
Two-toed and three-toed sloths are both found in Central and South American rain forest habitats, but that’s where the similarities end.
There are two species of two-toed sloths: the Linne’s two-toed sloth and the Hoffman’s two-toed sloth. Here at the National Aquarium, three Linne’s two-toed sloths can be found in the Upland Tropical Rain Forest exhibit. Two-toed sloths are more active than their three-toed counterpart. Three-toed sloths are incredibly slow moving (even slower than the two-toed sloth), and have the slowest metabolism of any mammal.
The two-toed sloth is nocturnal—meaning it’s only active at night—while the three-toed is active during the day and night.
When it comes to diet, the two-toed sloth tends to be the less selective of the two. The two-toed sloths at the Aquarium receive a wide-ranging diet, including green beans, carrots, zucchini, sweet potatoes and fruits, such as pears and grapes. The three-toed sloth tends to stick to leaves, shoots and juicy fruit.
While these two types of sloths are different in many ways, International Sloth Day is the time to celebrate both the two-toed and three-toed sloth!
Learn more about the two-toed sloths at the National Aquarium!